In a power converter for use on railway vehicles (hereinafter, simply referred to as a “power converter”), semiconductor switching devices (hereinafter, simply referred to as “switching devices”) included in the power converter are driven by drive signals from a gate drive circuit. The switching devices supply high-voltage and high-current power to a load by their on-off switching operations. At this time, inside the power converter, electromagnetic noise is generated in electrical wires included in the power converter.
In recent years, due to practical application of wide-bandgap semiconductor devices typified by Silicon Carbide (SiC), and due to increased performance of preexisting Si switching devices made from Silicon (Si), the switching speed of the switching devices has been increased. Due to the increased switching speed, the problem of electromagnetic noise generated from the electrical wires included in the power converter cannot be ignored.
In the background as described above, Patent Literature 1 described below focuses on electrical wires inside a module among electrical wires included in a power converter. A power semiconductor module (hereinafter, simply referred to as a “power module”) described in Patent Literature 1 discloses a technique in which an electrical wire inside the module connected to a positive electrode terminal, an electrical wire inside the module connected to a negative electrode terminal, and a gate signal line and an emitter signal line inside the module are provided with their respective parts disposed in parallel to form layers, and the direction of an electric current flowing in the positive electrode terminal is made opposite to the direction of a control current flowing in the gate signal line adjacent to the positive electrode terminal in the parts disposed in parallel, so as to reduce the possibility of malfunction of the switching devices repeating on and off operations both at the time of turning on and at the time of turning off.